Together, these aims will provide novel information regarding the impact of acid blockade treatment on the esophageal and lung microbiota that may impact management of respiratory disease in CF. We anticipate similar effects of acid blockade on the esophageal bacterial communities as we observed in non-CF pediatric and adult subjects, but acknowledge that treatment burden in CF, particularly antibiotics, may affect the expected outcome. These data will provide critical information to evaluate the effect of acid blockade on infection risk, which could affect therapeutic choices for patients with CF. The long-term goal of these studies, is to improve patient care by assessing the effect of acid blocker therapy on the microbiota and inflammation.